Seal for vapor electric devices



Get. 14, 193G AOK] 1,778,657

SEAL FOR VAPOR ELECTRIC DEVICES Filed Sept. 24, 1926 Inventor": SaharaAoki His Attorngy Patented Oct. 14, 1930 UNITED S ATES PATENT OFFICEsaraao aoxr, or HIRAISUKA, JAPAN, assranoa ro- GENERAL anaemic comramr,

A CORPORATION 01 NEW YORK SEAL FOR VAPOR ELECTRIC DEVICES Applicationfiled September 24, 1926, Serial No. 135,868, and in Japan October 18,1925.

My invention relates to means for sealin together the different parts ofthe wall of a vapor electric device such as a mercury rectifiercomprising a plurality of anodes mounted within an evacuated metal tank,and has i for its principal object the provision of an impervious sealthat does not deteriorate under the various operating conditions towhich vapor electric devices are subjected.

1o Satisfactory operation of a vapor electric device, such as themercury arc rectifier, requires that a fairly high vacuum be maintainedwithin the rectifier tank. In order to maintain such a vacuum, it isessential that only the most reliable packing be used between the metalto metal, and the metal to insulation joints of the vessel. Thoughrubber gaskets compressed between the parts to be joined are quiteeffective for this purpose,

it has been found that thesulphur content of the rubber combines withmercury vapor to form mercuric sulphide which destroys the insulatingproperties of the rubber and is likely to be the cause of destructiveshort circuits between parts of the tank charged to different voltages.F or these reasons the use of rubber as the sealing means between thedifferent parts of a mercury rectifier has heretofore necessitatedfrequent opening of the 3 tank to permit reconstruction of the seals.

In accordance with my invention, these difliculties are avoided bycoating the surface of the rubber with a material which is not affectedby oxygen and mercury, this material being applied by plating, painting,or in any other suitable manner.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying to drawing and itsscope will be pointed out in the appended claims.

The drawing illustrates a part of a mer cury rectifier wherein myinvention has been embodied.

This .rectifier comprises wall portions 1 and 2 which are electricallyinsulated from one another by means of an insulation member 3, andan-anode 4 which is'supported by the wall portion 2. Rubber packing 5 is1n-' terposed between the lower edge of the ing sulation member 3 andthe bottom of a groove 6 formed in the upper surface of the wall portion1 and a like packing is interposed between an annular rib 7 formed onthe lower surface of the wall portion 2 and the bottom of a groove 8formed in the upper edge of the insulation member 3. Bolts 9 areprovided for clamping the gaskets 5 between the upper edge of theinsulation member 3 and the wall portion 2 and between the lower no edgeof this member and the wall portion 1. The grooves 6 and 8 may be filledwith mercury.

The coating applied to the gaskets 6 and 8 may consist of any suitablemetal which does 5 not destroy the resilience of the rubber and is notattacked by mercury or may consist of graphite or the like painted onthe surface of the rubber.

The embodiment of the invention illustrated and described herein hasbeen selected for the purpose of clearly setting forth the principlesinvolved. It will be apparent,

owever, that the invention is susceptible of being modified to meet thedifferent conditions encountered in its use and I therefore aim to coverby the appended claims all modifications within the true spirit andscope of my invention.

What I claim as new and desire to secure so by Letters Patent of theUnited States, is:

1. A mercury rectifier seal structure comprising a plurality of wallsections, and a seal between said wall sections comprising a rubbergasket coated with a material not affected by mercury.

2. A mercury rectifier seal structure comprising a plurality of wallsections, and a seal between said wall sections comprising a rubbergasket coated with graphite.

3. A mercury rectifier seal structure comprising a plurality of wallsections, and a seal between said wall sections comprising a rubbergasket coated with graphite and submerged in'mercury.

In witness whereof, I have hereunto set my hand this 23d day of Au st,1926.

I S TARO AOKI.

